Stretch-reducing rolling mill

ABSTRACT

The disclosure of the application relates to a stretch-reducing rolling mill for tubes, including a number of tandemly arranged mill stands, and individual gear-motor drives for each stand. The mill stands include frames or supports which in an interchangeable manner receive either a three-roll head or a four-roll head, the former having a single drive shaft and the latter two spaced apart drive shafts. Between the gear motors and the stands there is provided for each stand distribution gear units having two output drive shafts, one being employed to drive the three-roll head and both to drive the four-roll head.

United States Patent [191 Ritter et al.

[451 Aug. 27, 1974 STRETCH-REDUCING ROLLING MILL Primary Examiner-Milton S. Mehr [75] Inventors: Hans Georg Ritual, Rheydt; Ulrich gttort'lney, Agent, or Fzrm-Henry C. Westm; Daniel Weiser, Monchengladback, both of Germany [73] Assignee: Wean United, Inc., Pittsburgh, Pa. d ABS 1 Ezaci2;at:gsitfsrtrsssizzifisrzg 32121522 [21] Ap 1,N0,;404,944 tandemly arranged mill stands, and individual gearmotor drives for each stand. The mill stands include f 52 vs. C] 72/235, 72/238, 72/249 2; si 2 2 the former having a single drive shaft and the latter l 0 c 3 9 two spaced apart drive shafts. Between the gear mo- 1 References Cited fiilffii fiififi ifi ffii iiifi fii'ifii fii'diii sii'i UNITED STA S PATENTS one being employed to drive the three-roll head and 3,016,772 1/1962 Hombostel 72/249 both to drive the four-roll head. 3,181,332 51965 V D 7 4 9 3 Claims, 4 Drawing Figures 2 3 4 5 6 7 a II I ll l l l I I l t I l T g 4-. l l Fl I I 12 :1? F 1 F"; s. P? PAP H L \l \l I" i I iT' i' I' E Ifz: .g I;: AI k K gl 6-41 I I 93 I I/LMJ'L'ZTQ {Flt-3| I -:i fjzzz -l l \JT 6 J I I J l P ,1 A ,l g t I \I I H r r I 7 -1 r l I 5 I L J L J L 1 L J L J L J L. .J L J I H H -1 r 1 65 H l I I l l I l l l I I l l l I I I J J. l J. .L J. .L

STRETCH-REDUCING ROLLING NHL The invention relates to a stretch-reducing rolling mill for tubes, comprising a plurality of stands which are arranged one behind the other in the rolling direction and which are each connected with a shaft to a superimposed drive arranged adjacent the row of stands, and comprise in the stand housings distribution gear units comprising at the roll head side two horizontal drive output shafts which are situated vertically one above the other and of which at least one is adapted to be coupled with a horizontal driving shaft, carrying a roll of the roll head, of an appropriate roll head adapted to be inserted in interchangeable manner in the stand housings.

It is an object of the invention to arrange a stretchreducing rolling mill for tubes in such a manner that both three-roll stands with a known bevel gear unit and only one driving shaft and also four-roll stands with two driving shafts can be used, without having to provide additional connecting gearing at the four-roll stands, and allowing a change-round to be made without relatively long stoppages.

This object is achieved according to the invention in that three-roll heads or four-roll heads can be fitted selectively in the stand housings provided with the distribution gear units, the inter-axes spacing of the two horizontal driving shafts of the four-roll heads carrying the two rolls of the four-roll heads situated one above the other being equal to the inter-axes spacing of the drive output shafts of the distribution gear unit and equal to twice the spacing of the horizontal driving shaft from the rolling axis of a selectively insertable three-roll head.

This solution represents an optimum adaptation to the conditions of practical use since only the spacings of the driving shafts of the four-roll heads have to be adapted to the spacings of the driven shafts of the distribution gear units. This is a problem which is solved from the constructional point of view, above all as compared with a four-roll head with a connecting gearing, whether flange-connected or an integral component part. The broader the program is as regards various tube dimensions, the more is an advantage obtained from the economic point of view owing to the simple construction of the four-roll heads already at the capital outlay stage despite the distribution gear units which have to be provided in the stand housings, since these remain unaltered for all tube dimensions, that is to say they only have to be provided once.

A further development of the invention which contributes to improved economy in the production of such tube reducing rolling mills proposes making the inter-axes spacing of the drive output shafts of all the distribution gear units identical to one another. Finally, the distribution gear units associated each with two adjacent roll heads can be arranged in a common gear housing.

The drawings show construction examples of the invention.

In the drawings:

FIG. 1 shows a plan view of a diagrammatically illustrated stretch-reducing rolling mill with eight stands,

FIG. 2 shows the fifth stand of FIG. 1 in detail,

FIG. 3 shows a detail from FIG. 2, and

FIG. 4 shows the sixth stand of FIG. 1 in detail.

The stretch-reducing rolling mill shown in FIG. 1 for the production of tubes having square shapes comprises eight stands arranged one behind the other in the rolling direction and arranged in a common stand housing 10. Corresponding to the eight stands, eight roll heads 1 to 8 are provided, namely five three-roll heads 1, 2, 3, 4, 5 and three four-roll heads 6, 7, 8. An arrow 9 indicates the rolling direction. Associated with each of the roll heads 2 to 8 is a distribution gear unit which is arranged in the corresponding part of the stand housing 10. The stand housing 10 can of course also be composed of individual housings corresponding to the number of roll heads, and it is also possible to arrange for example each two roll heads in one stand housing. The distribution gear unit is associated with the fifth stand equipped with a three-roll head 5, and the distribution gear unit 26 is associated with the sixth stand which is provided with a four-roll head. The connection of the distribution gear units 25 and 26 with the roll heads 5 and 6 is explained in detail in FIGS. 2, 3 and 4 in further examples. The drive of all the distribution gear units 20 is effected by means of a series of shafts 30 of which the shaft is associated with the distribution gear unit 25 and the shaft 36 with the distribution gear unit 26. The shafts 30 connect a series of preceding superimposed drives 40 with associated driving motors 49 with the appropriate series of distribution gear units 20. No distribution gear unit is provided in the first stand, since this is always provided in the present example with a three-roll head 1 which serves as an inlet head.

FIG. 2 shows how the fourth stand can be constructed. In the housing 10 a three-roll head 5 in this case is secured in an interchangeable manner. A releasable securing device 19 is used for this three-roll head. The three-roll head 5 itself lies on supports 19 which are provided in the stand housing 10.

The three-roll head 5 with three rolls 51, 52, 53 which together form a round pass, is driven by means of the horizontal driving shaft 55 driving the roll 51. A known bevel gear unit 54 is used for driving the other rolls 52 and 53. The driving shaft 55 is coupled by way of an appropriate releasable shaft coupling 21 which is only shown symbolically, with the upper drive output shaft 11 of the distribution gear unit 25. The distribution gear unit 25 again is driven by the shaft 35. Arranged on the upper drive output shaft 11 is a gear wheel 13 which engages with other gear wheels 14, 15 and 16, the gear wheel 16 being arranged on a lower drive output shaft 12 of the distribution gear unit 25. The lower drive output shaft 12 co-rotates idly in the present case. The distribution gear unit 25 itself is arranged in a housing 17 which can also receive the distribution gear unit of the preceding stand. This is shown as an example in FlG. 3, wherein the train of wheels of the neighboring distribution gear unit is designated as 18. The shaft which is connected in each case with one of the rolls is specially indicated. As can be seen, in the three-roll head 5 the upper shaft 11 is connected with the roll 51 whereas in the preceding stand the three-roll head is turned so that the other shaft is connected with the corresponding roll.

To explain the invention it should also be stressed that the inter-axes spacing b of the two drive output shafts 11 and 12 of the distribution gear unit 25 is twice as great as the inter-axes spacing c of the driving shaft 55 from the rolling axis.

In FIG. 4 as an additional feature the inter-axes spacing a of the two driving shafts 65 and 66 of a four-roll head 6 is shown. This FIG. 4 shows how the sixth stand can be constructed, and it will be apparent that instead of the four-roll head 6 shown here a three-roll head 5 as shown in FIG. 2 can be used. The four-roll head 6 comprises an upper roll 61 and a lower roll 63 and also two lateral rolls 62 and 64. The four rolls 61, 62, 63, 64 together form a rectangular pass. The upper driving shaft 65 is connected with the corresponding distribution gear unit 26 by way of its upper drive output shaft 11 The lower drive output shaft 12 of the distribution gear unit 26 is connected to the lower driving shaft 66 of the four-roll head 6.

In accordance with the provisions of the patent statutes, we have explained the principles and operation of our invention and have illustrated and described what we consider to represent the best embodiment thereof.

other, at least one of these shafts having means permitting it to be coupled with a horizontal driving shaft carrying a roll of a three-roll head, or to be coupled with two horizontal driving shafts carrying rolls of a four-roll head, which roll heads are to be inserted in an interchangeable manner in the stand housing, characterized in that one or more three-roll heads (2, 3, 4, 5) or one or more four-roll heads (6, 7, 8) selectively can be fitted in the stand housings equipped with the distribution gear units (20), said four-roll heads having rolls arranged in a superjacent manner, the inter-axes spacing (a) of said two horizontal driving shafts (65, 66) of a four-roll head (6, 7, 8) carrying said two superjacent rolls (61, 63) of the four-roll heads being equal to the inter-axes spacing (b) of said drive output shafts (11', 12) of the distribution gear unit (20) and equal to twice the spacing (c) of said horizontal driving shaft (55) from the rolling axis of a selectively insertable three-roll head (5).

2. Stretch-reducing rolling mill according to claim 1, characterized in that said drive output shafts (11,12) and (11', 12') of all the distribution gear units (20) have an identical inter-axes spacing.

3. Stretch-reducing rolling mill according to claim 1, characterized in that the distribution gear units (20) associated in each case with two neighboring roll heads are arranged in a joint gear housing (17).

UNITED STATES PATENT OFFICES, CERTIFICATE OF CORRECTION Patent No. 3,831,417 Dated u u 1, 1974 Hans-Georg Ritter et a1. Inyentor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet insert:

[30] Foreign Application Priority Data Dec. 15, 1972 Germany P 22 62 391.2

I Signed and sealed this 14th day of Jann ary 1975.

(SEAL) Attest:

McCOY M. cnsson JR. c. MARSHALL DANN; Attesting Officer Commissioner of Patents USCOMM-DC 80376-P69 u.s. sovznuueu'r wnm'nuc orncs: 8 93 0 FORM PO-IOSO (10-69) 

1. Stretch-reducing rolling mill for tubes, comprising a plurality of stands each having roll heads and arranged one behind the other in a row in the rolling direction and each connected with a shaft to a respective drive arranged adjacent the row of stands, stand housings distribution gear units driven by said shafts and having at one side of each of the roll heads two horizontal drive output shafts situated vertically one above the other, at least one of these shafts having means permitting it to be coupled with a horizontal driving shaft carrying a roll of a three-roll head, or to be coupled with two horizontal driving shafts carrying rolls of a four-roll head, which roll heads are to be inserted in an interchangeable manner in the stand housing, characterized in that one or more three-roll heads (2, 3, 4, 5) or one or more four-roll heads (6, 7, 8) selectively can be fitted in the stand housings equipped with the distribution gear units (20), said four-roll heads having rolls arranged in a superjacent manner, the inter-axes spacing (a) of said two horizontal driving shafts (65, 66) of a four-roll head (6, 7, 8) carrying said two superjacent rolls (61, 63) of the four-roll heads being equal to the inter-axes spacing (b) of said drive output shafts (11'', 12'') of the distribution gear unit (20) and equal to twice the spacing (c) of said horizontal driving shaft (55) from the rolling axis of a selectively insertable three-roll head (5).
 2. Stretch-reducing rolling mill according to claim 1, characterized in that said drive output shafts (11, 12) and (11'', 12'') of all the distribution gear units (20) have an identical inter-axes spacing.
 3. Stretch-reducing rolling mill according to claim 1, characterized in that the distribution gear units (20) associated in each case with two neighboring roll heads are arranged in a joint gear housing (17). 